Forward and reverse turbine operated by combustion products and air



July 26, 1949.

R. J. IMBERT ETAL 2,477,184 FORWARD AND REVERSE TURBINE OPERATED BY COMBUSTION PRODUCTS AND AIR Filed June 11, 1945 camel/$710 can/vase e FUEh HED WEB/IVE F 1 PEI/625E THEE/NE Fig.2

B7 GAS-a Mi k t I FORWARD. AND

Roger Imbert and Marcel-Henri Sdille, Paris, France, assignors to- .Socite' Bataan ('Socit Anonyme). Paris, France, I. company of France, and Ren Anxionnaz, Paris, I

France, jointly Application June 11,1945, Serial No. 598,768 In France October 26, 1942 r 1 In power machines comprising gas turbines, the high temperature of the gases and the considerable inertia of the moving masses make it difiicult to execute reversals in speed, either from forwardto backward movement or reversely, unless mechanical reversing means are resorted to.

The present invention relates to the case where thepower required for rearward operation is much less important than thatrequired for normal forward operation, as may be the case with ships for instance.

According to the invention, the rearward motion is obtained by means of a gas turbine fed with the gases removed at the outlet of a recuperator without said gases being submitted to a complementary heating in a combustion chamber.

The following description to beread in association with accompanying drawing, of a form of execution given by way of example and by no means in a limitative manner, will, allow the execution of the invention to be well understood; the features appearing either in the drawing or in the specification form of course part'of said invention.

different forms of execution of the invention.'

There is shown diagrammatically in Fig. 1 a thermio engine with gas turbines adapted todrive a ship's propeller and including an auxiliaryturbine for driving the aircompressor. Insaidfigure, a designates the'air compressonb' the aux-' IClaim. (01. 60-49) v mitted to the very high temperature of the comof the combustion chambers, the-isolating parts being arranged in the path of thegases passing at alower temperature out of the recuperator, Thus Fig. 2 shows the valve or inserted upstream with reference to the combustion chamber Figs. 1, 2 and 3 show diagrammatically three iliary gas turbine driving same, 0 the combustion chamber cooperating with the auxiliary turbine and with the principal driving turbine at. The

latter drives thepropeller. p for forward motion;

e designates the driving-turbinefor rearwardmo tion and f the heat exchanger or recuperator of the principal driving turbine d for 'forward operation. use or the moderate amount. of power required for 'therear operationturbine e for feeding the latter .with compressed air which has already The invention consists in making.

passed through the heat exchanger f without any complementary heating due to a combustion of fuel inside said air. Inorder to ensure under such conditions the feeding, as desired-of either driving turbine, the turbine d for forward nio- ];tionon' one hand and the turbine e for rearward motion on the other ,hand may be selectively isolated through actuation of the valves m m-. v 1 This arrangement shows'however the drawback consisting in that the valve m or th'elike' isolating part for the forward operation turbine is-subbustion gasespassing out of the burners in the combustion chamber 0. V

In order-to remove this drawback, it is possible to provide in conformity with Fig. 2 a similar arrangement in which two combustion chambers are used of which one, or feeds the auxiliary turbine b with hot compressedgases while the other, 02, feeds the principal driving turbined for forward motion with hot compressed gases.

This latter arrangement shows the double advantage- 1. Of allowing the driving turbine d to be fed at the maximum temperature allowed by reason of the possiblefiow of the metal without any other consideration as to the balance of power between the power of the auxiliary turbine and that absorbed by the air compressor.

2. Of inserting no isolating valve or the like part .in the path of the hot gases at the outlet At the outlet of thedriving turbine for forward motion, the exhaust gases may or may not pass through the heatrecuperator ,f; the case is the same for the exhaust gases passing out of the driving turbine for rearward motion.

The invention covers also the recuperation of I the hot gases which have passed through the recuperator and which itis necessary to remove when they are available when the turbines for v forward or rearward motion operate at zero 3 power or have stopped. In conformity. with'the diagramof Fig. .3, a'small elementary gas turbine Q a I h similar to'the rear motion turbine and: fed

solely'by means of the gases which have passed through the recuperator is coupled with the,

- system comprising the auxiliary turbine b and the f compressor-a. -A valve 03' allows inserting said, I turbine in the circuit ioroperation in order to.

provide for the working of the motor, when idling,

with a. lesser expenditure offuel. the flow'of fuel inside the chamber or being then-reduced, I In allcases '(Figs. 2 and 3), the burner in the combustion chamber ofthe driving turbine. for forward motion may, during idling operation, be held operating at a very'low rate with the minimum corres'pondingiiiow of air. Thisjarran'gement allows therefore a very'specdy passage from I air-23 1134t 3 forward operation to rear operation and reversely, which furthers thus the ease of manoeuvring which is highly to be appreciated in particular on board warships.

The essential condition to be observed in all cases is the obtention oi the highest temperature possible in all the turbines and at all rates of running.

Obviously, the forms of execution described have been given solely by way of example and by no means in a restrictive sense and they may be modified for instance by replacing a given part by an equivalent device without widening thereby the scope of the invention, as defined by accompanying claim.

What we claim is: i

In a gas turbine plant for driving ship propellers. having a gas turbine, for forward motion of the driven apparatus. another gas turbine i'or rearward motion and a common source of air under pressure comprising an air compressor and an auxiliary gas turbine for driving the same, the combination which comprises a heat exchanger ior receiving, in heat exchange relation, the whole of the exhaust gases of both the first named gasturbine and the auxiliary gas turbine and also the air under pressure delivered by said compressor, pipin means connecting the outlet 0! said heat exchanger to said forward motion gas turbine and to said auxiliary gas turbine, ior conducting the heated air to said turbines respectively, said piping means comprising a combustion chamber and valve means ahead of REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES Number Name Date 1,269,492 Nagelmann June 11, 1918 2,322,987 West -'June 29, 1943 FOREIGN PATENTS Number Country 1 Date 493,174 Great'Britain Oct. 4, 1938 

